The present invention relates in general to a measuring device, and more particular, to a transparent measuring device that provides a guide for facilitating seam allowance for cutting or marking materials or fabrics into various patterns.
The introduction of the rotary cutter and acrylic rules has changed quilting dramatically. Instead of using individual templates or patterns and scissors, a user could simply measure the fabric through a clear acrylic ruler and cut a straight edge with one motion. A couple of short cuts were also developed for some of the more commonly used shapes in quilting. Two examples of such short cuts are the half-square and quarter-square triangles made by first cutting a square and then cutting the square in halves diagonally once for half-square triangles or twice for quarter-square triangles. Though easier compared to using an individual template or pattern, this procedure can still be confusing to the average quilter to add the proper amount of seam allowance.
Seam allowance is the amount of fabric that will be taken up in joining the individual pieces together by sewing. The joined portions end up on the inside of a quilt and therefore do not add to the dimensions of the quilt. Quilters refer to these pieces as the unfinished size before they are joined together and as the finished size after they are joined together. The most common seam allowance is ¼″. To cut a square or a rectangular shape, ½″ has to be added to the finished size, that is, each side of the unfinished size is typically ½″ longer than that of the finished size. For example, if a 2″ square finished size is required, a square with each side of 2½″ has to be cut. The seam allowance is ⅞″ for a half-square triangle and 1¼″ for a quarter-square triangle. Therefore, to cut a half-square triangle with a finished size of 2″, a square with each side of 2 and ⅞ inches is required to leave an extra ¼″ around the triangles to be sewn into the seams. For a quarter-triangular finished size, each side of the square of unfinished size has to be 1¾″.
In addition to the different seam allowances that may confuse quilters, conventional rulers and yard sticks have several other disadvantages when being used for cutting fabrics with various colors and patterns. For example, it is inconvenient to lift and move the rulers and the yard sticks with a larger surface area, and the marks and lines on transparent rulers and yardsticks are often difficult to see when the fabric to be marked is similar in color to the ruler. Further, the angle measurement is often restricted to the number of angled lines and markings formed on the ruler and the yard sticks.
It is therefore a substantial need to provide an easily handled measuring device that provides clear and precise marking and cutting aids even when the fabric to be marked or cut has a dark color. The measuring device should also provide a seam allowance guide for at least the commonly used quilting shapes such as square, half-square triangle and quarter-square triangle.